Implement a function to visualize an object at xyz coordinate

This is a useful feature to show the subgoals predicted by a meta policy of a hierarchical model, or to visualize the predicted end effector position by a forward model.

See this example with the purple box as being the predicted subgoal:

@Matin, for this, you need to reuse or define dummy objects that you place appropriately. We should have an old branch with a subgoal wrapper somewhere, where you can find the scaffolding for this approach.